There is known a tandem-type color laser printer of an electrophotographic type. This color laser printer is provided with a plurality of photosensitive bodies and a plurality of developing units in one to one correspondence with the photosensitive bodies. The photosensitive bodies are in correspondence with toners of four colors of yellow, magenta, cyan, and black. The photosensitive bodies are juxtaposed with one another and are arranged in a predetermined direction. The developing units are for supplying toner of corresponding colors to the photosensitive bodies.
One example of the color laser printer of the above-described type includes: a drawer unit that retains a plurality of photosensitive drums in correspondence with toner of respective colors; a plurality of developing cartridges each retaining a developing roller; and pressing cams and separating cams that are provided in the drawer unit for bringing the developing rollers and the photosensitive drums into and out of contact with each other.
In such a color laser printer, the pressing cams press the developing cartridges to bring the developing rollers into contact with the photosensitive drums. When the separating cams are actuated, the separating cams release the contact between the developing rollers and the photosensitive drums and separate the developing rollers and the photosensitive drums from each other.